This invention concerns car wash conveyors of the type using a chain driven pusher rollers selectively elevated to engage a tire of a vehicle to advance the vehicle along a track on which the vehicle tires roll.
U.S. Pat. No. 4,864,936 describes a particular roller assembly, conveyor track section, and chain tensioner-ramp assembly for a car wash conveyor of this type. The conveyor track sections have intermediate and lower tracks for idle and return travel of the rollers, so that three tracks are provided including the upper track on which the activate rollers roll.
The track structure described therein has a frame of upright angles welded to longitudinal steel angle members forming upper and lower tracks. An intermediate track comprised of thick plastic angles resting on steel angles and are bolted through holes in the upper and vertical leg of the steel angle. Separate upper pieces support lateral tire guides.
The use of vertical angles as the main frame support establishes that the intermediate and lower tracks to be of equal width. Since the intermediate track is defined by the combination of a single steel angle and a plastic angle, the lower track, which is constructed of a steel angle alone, is somewhat wider. This allows the chain to wander, increasing chain wear by the lack of confinement of the chain rollers.
This construction also involves extra labor in locating and drilling holes for the plastic angles, as well as in separately constructing and attaching the upper tire guide support pieces. The longitudinal members also vary in length, adding to the complexity of fabricating the track structures.
The entrance section of such conveyors includes a chain tension take up mechanism, including a take up drum around which the conveyor chain passes the take up drum mounted on slides and spring urged outwardly to establish proper chain tension. A roller control mechanism is also located at the entrance section for causing a selected roller to move up a ramp onto the upper track where it can engage a vehicle tire. The roller control includes a pair of ramp members connected to form a pivoted fork, which when raised by an actuator, diverts the rollers on one end of the next roller assembly to be guided up to the upper track for engagement with the next vehicle""s tire.
These mechanisms are mounted to two of the longitudinal frame pieces extending between vertical angle pieces. If maintenance is required on either mechanism, this location makes it difficult to work on, and/or to remove the mechanisms for service.
The fork member in the roller control mechanism has rubber cushions installed on impacting portions to quiet the operation, but these cushions typically become dislodged such that noisy operation results.
The take up drum is mounted on bearings which are located within the frame and are difficult to reach for routine maintenance and subjects them to water and dirt dripping down from the car wash sprays and dirt curved down with the spray water.
Accordingly, it is an object of the present invention to provide a simpler, track construction for a car wash conveyor which can also easily provide properly spaced track sections for the lower track.
It is another object to provide a tension take-up and roller control fork mechanisms for a car wash conveyor which allows easier access for maintenance, and improves the performance of those mechanisms in service.
These and the other objects of the present invention which will become apparent upon a reading of the present specification and claims are achieved by constructing the track structure with the use of support frames cut out from plate stock to have webs for supporting the top, intermediate, and lower tracks.
The support frames allow the opening for the intermediate track to be wider to compensate for the thickness of the plastic angles and the lower track opening narrower to provide close guidance of the conveyor chain and rollers.
The support frames have integral tire guide roller supports to eliminate the need for separate support pieces.
The upper track comprises inverted angles which are spaced from an upper leg of an intermediate track support angle to form a lengthwise slot on each side of the track structure.
The plastic track angles are fastened by bolts passed through the slot and holes in the plastic tracks to eliminate the need for drilling holes in the metal pieces aligned with the holes in the plastic track angles.
The roller control and chain take up mechanisms are mounted at the entrance of the conveyor as a self contained a unit comprised of two pairs of parallel rods connected at each end to a respective end plate. The entrance track section is configured to allow easy removal of this unit without disturbing the track structure.
The take up drum support shaft is rotatably mounted on a pair of side support plates each slidable on journals received on respective one of the pairs of the rods. Bearings for the drum support shaft are installed on the outside of the side support plates to enable ready access and to minimize exposure to the water spray and drippage.
The fork of the roller control mechanism is carried on a pair of support side plates which are adjustably mounted on the four rods of the unit assembly. Two sets of cushioning stops are securely mounted to side and end plates located to engage fork members to quiet the operation thereof.
The entire assembly is readily detachable to be removed from the entrance track section as a complete unit for convenient servicing.